A comprehensive review of the characterization of raw and surface-modified cellulosic plant fibers and their polyester- and epoxy-based composites.

This review provides detailed information about the extraction and characterization of different cellulosic plant fibers, which are primarily composed of biological macromolecules such as cellulose, hemicellulose, and lignin. The properties of plant fibers vary based on parameters such as extraction methods, plant maturity, the part of the fiber-yielding plant, and soil conditions, which drive researchers to study the various properties of cellulosic fibers before using them as reinforcement in polymer composites. Properties such as density, diameter, functional groups, thermal stability, tensile properties, crystallography, and surface morphology were investigated using various characterization methods discussed in this article. Different surface modification techniques, especially chemical methods, are discussed, and their impacts on various properties of the fiber are also reviewed. The mechanical properties of fiber-reinforced plastics depend on the weight percentage of the fiber, fiber surface condition, fiber length, fiber orientation, secondary filler usage, and manufacturing method. By optimizing the mechanical properties of plant fiber-reinforced composites, this research paves the way for their application in the automotive and construction sectors, where lightweight and durable materials are required. This review analyzes the mechanical properties of composite materials in relation to varying manufacturing parameters, with a particular focus on cellulose-rich fibers and their contribution to the performance of polymer composites.